Flow tested walbro 255lph hp pumps leading to disappointment.

[____Kurt____]

So I am in the middle of a dual walbro intank installation and was curious was these pumps truly flowed to make sure they were parallel and one wasn't flowing less than the other. The pumps are brand new keep in mind. I setup 2 one gallon containers and ran 3 liters of gas per test. I had a battery charger hooked up to a brand new battery with alligator clips going to the pump. The pump was tested at 0 psi first and then at 37psi with a regulator. At 0 psi the pumps flowed 3 liters in 33.4 seconds and at 37 psi it flowed 3 liters in 44.7 seconds. If my math is right then it would be flowing 323lph at 0 psi and 240.9 at 37psi. From what I understand these pumps are rated at 255lph at 40psi.
What do you think about this?

 

[victorious420]

I'd bet your battery charger is part of the issue. Perhaps not sending enough amperage to the pump for the pump to work at peak capacity? I know my battery charger has multiple amperage settings, from 1 amp trickle, to 60 amp starting/fast charge.

 

[Purple_Demon]

I hope its something wrong with the battery setup...I just put money in my paypal account to order a 255hp today :/

Might have to run a bosch 044 inline just incase

 

[hediki12]

What voltage was it getting?

 

[hediki12]

Also what type of fuel?

 

[silvreclips]

I wouldnt be to worried about it. You need to find out what voltage the pumps are rated at. If you are testing at 12.5v and they are testing at 14v you will see a pretty big difference. Also yo u are only about 7-8% off. I am not to convinced that your testing method is completely accurate and think that is an acceptable margin of error. Even the temp of the fuel could factor in.

Think about all of your possibilities for error.

- The start/stop of the clock
- The voltage
- Ramp up of the pump
- Measuring exactly how much fuel you pumped.

Assuming you were only off a little on each item you I would be very surprised if you got exactly what they are claiming.

 

[bastarddsm]

Also who cares what they flow at 37psi. You best check them at 80psi, as thats where you will need the flow, when your boost gets up.

 

[hediki12]

Also who cares what they flow at 37psi. You best check them at 80psi, as thats where you will need the flow, when your boost gets up.

Yea i was thinking the same, worry about how accurate is is from 60-80 psi thats more than likely the pressure you will be seeing at a 40psi base plus boost

 

[____Kurt____]

All these are variables that can throw off what they are really pumping. The fuel I was using is 110oct race gas that I have laying around (don't ask). I have both containers measured to 3 liters. I did this test multiple times and found it is more accurate to clock the container with the pump because the gas steadily goes down and resulted in much more consistent flow times (44.7,44.7,44.7,44.6,44.9). One major problem is that I do not have a volt meter with me right now (at the shop) so I have been considering low voltage the main reason for lower flow rates. The battery was on charge at 6 amps. I was going to try the pumps at 80 psi but I don't have any fuses in the wiring I using and I would hate to over run anything because even at 37psi the alligator clips were getting toasty at the end of each test. I will grab some pictures and hopefully video tomorrow along with my volt meter.